Refrigerator evaporator



Feb. 1 9, 1935 REFRIGERATOR EVAPORATOR Filed Feb. 24, 1933 His Attorney c. STEENSTRUP 1,992,018

fPatented Feb. 19, v1935 I UNITED STATES PATENT OFFICE A f 1,992,018 REFRIGERATOR nvarona'roa Christian Steenstrup, Schenectady, N. Y., as-. signor to General Electric Company, a corporation of New York My invention relates to cooling units for refrigerating systems, and more particularly to such cooling units having a removable section which may be detached or secured'to the unit without 5 any interference with the closed circuit of the refrigerating system.

The refrigerating machines heretofore em-' compressor and condenser units of such capacity that they will operate satisfactorily in any one of twoor more. ofthe different standard size cabinets, the only change necessary being in the capacity'of the evaporator used. It has been the practice to construct compressor and condenser units of standard sizes, each'having connected thereto cooling units .of a capacity selected according to the size of cabinet to be used with each compressor and condenser unit. These cooling units cannot be removed from the compressor and condenser unit without opening the closed refrigerating system, which is undesirable because air and moisture may enter the system.

When this complete refrigerating machine is installed in the field it may be desirable to place 25 the machine in a cabinet of'a size different from that for which the machine was made. This requires disconnecting and removing the cooling unit from the. closed refrigerating system and connecting thereto another cooling unit of the desired capacity, which cannot be conveniently accomplished in the place where the machines are installed. This has, therefore, made it difficult to replace or repair the evaporators, if necessary, on account of leaks or damage to the enamel or other finish which is usually employed.

An object of my invention is to provide a cooling unit construction in which the capacity can be conveniently changed as desired withoutopen- 4O ing the closed refrigerating system.

Another object of my invention is to provide a cooling unit for refrigerating machines having separate sections; one of which may beattached or detached without disturbing the sealed connections between the evaporator and the refrigerating system with which it is used.

Another object of my invention is toprovide a cooling unit for refrigerating systems having the main body thereof removable without disrupting the connections between the cooling unit and the remainder of the refrigerating system.

Further objects and advantages of my invention will become apparent as the following description.

proceeds and the features-of novelty which char- 55 acterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference'may be had to the accompanying drawr ing in which Fig. 1 is a perspective view of a two-' 6 section cooling unit embodying my invention;

'Fig. 2 is a fragmentary longitudinal sectional ployed in household refrigerators commonly have of the evaporator shown in Fig. 1 taken on the 10 line 33 of Fig. 2; Fig. 4 is a front elevation of a household refrigerator equipped with a cooling unit construct'ed'in accordance with my invention; and Fig. 5 is a perspective view, partly in section, of a modified form of cooling unit eml5 bodyi'ng my invention.

Referring to the drawing, in Fig. 1 I have shown a cooling unit having. a primary evaporator of the flooded type comprising a header 10 provided with legs 10a for securing it to a refrigerator cabinet top, and a depending wall 11 having circulatory passages for refrigerant leaving and returning to the header 10. As shown in Fig. 2, the wall 11 comprises an inner shell 12 and an outer shell 13 provided with corrugations 14, which cooperate with the inner shell to form the refrigerant circulating passages. The header 10 is provided with an inlet 15 for admitting liquid refrigerant to the evaporator and the level of liquid refrigerant in the header is maintained above the upper end of the passages in the wall 11. The gaseous refrigerant is withdrawn from the evaporator through an outlet 16. This evaporator is of the construction described and claimed in my copending application, Serial No. 389,050, filed August 28, 1929, and-assigned to the same assignee as this invention.

In accordance with my invention, I provide a second section, or secondary evaporator 17, re-' movably secured to the section 11 by thumb screws 18, one of which is arranged on each side of the evaporator, and which are threaded on rods 19 pivoted to the secondary evaporator 1'7 and engaging slotted lugs 20 secured to the wall 11 of the primary evaporator. As can be seen in Figs. 2 and 3, the secondary evaporator 17 is formed of an inner shell 21 and an outer shell 22 provided with corrugations 23 in contact with the inner shell and forming refrigerant circulating passages. This secondary evaporator is also provided with transverse openings or manifolds, the upper manifold being formed by a fold being formed by depressions 25- in corrugations in the outer shell 22. The secondary evapbetween the evaporators when thuinbscrews 18 are tightened.

In Fig. 4 I have shown a household refrigerator comprising a condenser and compressor unit 26 mounted on a cabinet 27 within which is arranged an evaporator 28 constructed as shown in Fig. 1, and within which evaporator are arranged.

freezing trays 29. In the operation of this system, refrigerant is compressed and condensed to aliquid in the compressor and condenser unit '26 and flows through a flow control device 30 from whence it flows to the header 10 in regulated quantities. Heat is absorbed by the refrigerant in the evaporator section 11 and a portion of the refrigerant is vaporized thereby, and the vaporized refrigerant collects in the header 110 from whence it is drawn back into the compresson and condenser unit 26 through the suction conduit to the compressor.. Since the upper portion of secondary evaporator 17 is in direct.

- heat exchangerelation with the wall 11, it is cooled thereby, and the gaseous refrigerant ,in'

this upper'portion is condensed as the heat is extracted from it, and the condensate flows back to the bottom of the evaporator to the main body of liquid refrigerant therein. Heat absorbed by the liquid refrigerant in the secondary evaporator, which is extracted from the air in the refrigerator cabinet and the freezing trays vaporizes the liquid and the vapor rises and gives up'its heat at the topof-the sectionin the manner just described. This cycle is continuous. No refrigerant is added to or withdrawn from the evaporator'l'l during its operation and it is completely sealed from the rest of the system. Should the capacity of the cooling unit shown in Fig. 4 be too great for the cabinet 27, or should it bedesiredto use the refrigerating machine in .a smaller cabinet, then the secondary evaporator 17 may be removed from the cabinet by looseningthe thumbscrews' 18. It is thus apparent that the evaporatonas shown in Figs. 1 and 4 is so constructed as to be available for usein either of two or more sizes of refrigerator cabinet. All the refrigerator units for either sizeof cabinet may be shipped from the factory with identical standard size evaporators connected in the circuit... When a refrigerator is installed, one of the standard units can be placed in the cabinet and'if the cabinet is of the larger size one or more of the secondary evaporators can be attached. to the primary evaporator supplied with the unit.

In Fig. 5 I have illustrated a modified form of.

my invention comprising av cooling unit the greater portion of which is removable without requiring the disconnection of the refrigerant circuit. 1 have also shown this'modification as constructed of cast metal, although this is not essential to the invention, as sheet metal or other types of construction may be used. In this construction I' provide an evaporator of the flooded type comprising a header 31 and a depending refrigerant circulating section 32 communicatingwith the header through tubes 33.,

The header 31 is provided with a connection 34 for admitting liquid refrigerant thereto and a connection 35 for withdrawing gaseous refrigerant therefrom. The liquid refrigerant in the header 31 is maintained approximately at the level indicated $17.36. The depending section 32 is in the form of a flat plate having a plurality of refrigerant passages formed therein. In accordance with my invention I provide a hermetically sealed removable section or secondary evaporator 37 partially filled with liquid refrigerant and having a fiat top arranged to be secured incontact with the section 32 by screws 38. Within the cast walls of the evaporator 3! are formed refrigerant circulatingpassages 39 connected by transverse openings 40.- These walls form a freezing compartment arranged to accommodate trays for freezing water, puddings. and the like. The outer surfaces of the secondary evaporator are large enough to cool the air circulatedinthe refrigerator cabinet in which the cooling unit is used. The operation of this modification is the same as that described in connection with the previous modification. The advantage of this modification lies in the arrangement whereby the main body of the evaporator having a compartment for trays may be removed without opening the refrigerant circuit if this becomes necessary on account of leaks or damaging of the porcelain enamel or other finish employed. The main body of the evaporator is inore likely to be damaged than the other portions thereof, because the ice trays freeze,to the bottom of their compartments and are usually forcibly loosened."

It is evident from the foregoing that I have provided a refrigerator cooling unit of such a' constructionthat its capacity may be changed by removal of a portion of the cooling unit with out interfering in any way'with the sealed refrigerant circuit, and that I have also provided a cooling unit, the main portion of which may be removed without interfering" with the refrigerant circuit.

Although 'I have shown a particular embodiment of my invention in connection with a compression refrigerating machine and a flooded evaporator, I do not desire my invention to be limited thereto, and intended in the appended a claims to cover all modifications within the spirit and scope of my invention. What I claim as new and desire'to secure by Letters Patentof the UnitedStates, is: I

1. A cooling unit for a refrigerator cabinet including a primary evaporator and a hermetically sealed secondary evaporator partially filled with liquid refrigerant and remcvably secured 1 thereto, said secondary evaporator having a compartment for. freezing trays and having a portionabove the level-of liquid refrigerant in said secondary evaporator in heat exchange relation with said primary evaporator, said primary and secondary evaporators having surfaces for cooling air in the refrigerator cabinet.

. l0 2. A cooling unit for a. refrigerator cabinet including a primary evaporator havinga compartment for freezing trays and a hermetically sealed secondary evaporator partially filled with liquid refrigerant, said secondary evaporator having a a compartment for freezing traysand having a portion above the level of liquid refrigerant in said secondary evaporator'in heat exchange relation with said primary evaporator, said primary and secondary evaporators having surfaces for cooling air in the refrigerator cabinet, said secondary evaporator being removable from said primary evaporator to reduce the heat absorbing capacity of said cooling unit.

3. A cooling unit for a refrigerator cabinet including a primary evaporator having a relatively thin fiat refrigerant containingmember, a header secured to said member and a hermetically sealed secondary evaporator partially filled with liquid refrigerant and having a flat surface above the level of liquid refrigerant therein in heat exchange relation with said refrigerant containing member, said secondary evaporator being removable from said primary evaporator, said primary and secondary evaporators having surfaces for cooling air in the refrigerator cabinet.

4. A cooling unit for a refrigerator cabinet including a primary evaporator having a corrugated surface .and a hermetically sealed secondary evaporator partially filled with liquid refrigerant, said secondary evaporator having a corrugated portion above the level of liquid refrigerant therein in heat exchange relation with the corrugations in said primary evaporator, a portion of the corrugations on said secondary evaporator conforming to a portion of the corrugations on said primary evaporator, said primary and said secondary evaporators having surfaces for cooling air in the refrigerator cabinet.

5. A cooling unit for a refrigerator cabinet including a primary evaporator provided with a header and having a relatively thin flat refrigerant containing member, and a hermetically sealed secondary evaporator partially filled with liquid refrigerant and removably secured in'heat exchanging relation to said refrigerant containing member, said secondary evaporator having a compartment for freezing trays, said primary and said secondary evaporators having surfaces for cooling air in the refrigerator cabinet.

6. Acooling unit for a refrigerator cabinet including a primary evaporator provided with a header and a corrguated refrigerant containing member, means for supporting said. primary evaporator within the refrigerator cabinet, and a hermetically sealed secondary evaporator removably secured to said primary evaporator, said secondary evaporator having a corrugated surface and being partially filled with liquid refrigerant, the corrugations of said primary and said secondary evaporators conforming to provide goodheat exchange between them, said primary and said secondary evaporators having surfaces for cooling air in the refrigerator cabinet.

,7. A refrigerator.cabinet, a cooling unit arranged in said cabinet, said cooling unit including a primary evaporator and a hermetically sealed secondary'evaporator partially filled with liquid refrigerant and removably secured to said primary evaporator in heat exchange relation therewith, said secondary evaporator having a compartment for receiving freezing trays.

CHRISTIAN STEENSTRUP. 

